(;GM[1]FF[4]SZ[4:2]
GN[Is W1 forcing?]
PC[http://senseis.xmp.net/?MathematicalTermForce]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?MathematicalTermForce

Is W1 forcing?]
PL[W]

AB[ab][bb][cb][db]

;W[ba]C[W1]MN[1]
;B[ca]C[B2]MN[2]

;
)
